Fuel tank and cap device thereof

Abstract

A fuel tank and a cap device for the fuel tank. The fuel tank is connected to a fuel cell and includes a tank body having a fuel opening and a pin hole for maintaining an inside pressure, a floater positioned on a surface of the fuel stored in the tank body, and an air pipe connected to the pin hole and an upper part of the floater. The cap device includes a cap body having an inside transfer path for connecting an inlet opening for introducing the fuel and an outside transfer pipe, a fixed outer cap including a connector for fixing a discharge opening into which the transfer pipe is inserted, and an elastic opening/closing section in which the cap body is elastically compressible by the connector, and wherein the inside transfer path opens during the compression.

1. A fuel tank for a fuel cell comprising,
 a tank body for storing fuel, the tank body having a threaded wall defining a fuel discharge opening; 
 a cap covering the fuel discharge opening and coupling the tank body with a transfer pipe for transferring fuel from the tank body through the fuel discharge opening, the cap comprising a threaded fixed outer cap screw-coupled to the threaded wall defining the fuel discharge opening such that there is a gap between the threaded fixed outer cap and the threaded wall, wherein the cap has a pin hole providing an open two-way air path between inside the tank body and outside the fuel tank for maintaining an inside air pressure applied to fuel stored in the tank body; 
 a floater having a lower portion positionable in the fuel stored in the tank body and an upper portion exposed to air in the tank body; and 
 an air pipe having a cap end and a fuel end, the cap end being connected to the pin hole and the fuel end being connected to the upper portion of the floater. 
 
     
     
       2. The fuel tank of  claim 1 , further comprising a fuel pipe coupled to the cap for transferring fuel in the tank body to the cap. 
     
     
       3. The fuel tank of  claim 1 , wherein the cap further comprises:
 a cap body having an inside transfer path for coupling a fuel inlet opening of the cap body to the transfer pipe; 
 wherein the fixed outer cap has a cap discharge opening and a connector, the outside transfer pipe being inserted into the cap discharge opening and the connector fixing the outside transfer pipe to the cap discharge opening; and 
 wherein the cap further comprises an elastic opening/closing section mounted in the cap body, the elastic opening/closing section being adapted to open the inside transfer path upon insertion of the connector into the cap body. 
 
     
     
       4. The fuel tank of  claim 3 , wherein the connector includes a connector body in the cap discharge opening;
 wherein the connector has a hollow pipe shape, 
 wherein an end of the connector has a connector flange having a diameter larger than a diameter of the cap discharge opening; and 
 wherein a hollow insertion member is in the transfer pipe. 
 
     
     
       5. The fuel tank of  claim 3 , wherein the elastic opening/closing section comprises:
 an opening/closing housing including a spring and an opening section at one side of the housing, and 
 a head section biased toward the connector by the spring, the head section opening the inside transfer path when the connector is in the cap body. 
 
     
     
       6. The fuel tank of  claim 3 , wherein the cap body is screw-coupled with the threaded wall defining the fuel discharge opening. 
     
     
       7. The fuel tank of  claim 3 , wherein the pin hole is on the cap body and allows access to an exterior of the fuel tank through the gap between the fixed outer cap and the fuel discharge opening of the tank body. 
     
     
       8. The fuel tank of  claim 1 , wherein the cap is adapted to prevent fuel from being transferred through the cap before a transfer pipe is inserted into the cap and is adapted to allow fuel to be transferred through the cap in response to a transfer pipe being inserted into the cap. 
     
     
       9. A cap for covering a fuel opening of a fuel tank comprising:
 a cap body having an inside transfer path for coupling a fuel opening of the cap body to an outside transfer pipe and a threaded outer peripheral surface for coupling the cap to a threaded wall defining the fuel opening; 
 a fixed outer cap having a cap discharge opening adapted to engage the outside transfer pipe, a connector adapted to fix the outside transfer pipe to the cap discharge opening and a threaded inner peripheral surface for coupling the cap to the threaded wall defining the fuel opening such that there is a gap between the fixed outer cap and the threaded wall; 
 an elastic opening/closing section in the cap body, the elastic opening/closing section being configured to open the inside transfer path in response to insertion of the outside transfer pipe into the cap body; and 
 a pin hole for maintaining an inside pressure of the fuel tank, the pin hole providing open two-way access between inside the fuel tank and outside the fuel tank through a gap between the fixed outer cap and the fuel opening. 
 
     
     
       10. The cap for a fuel tank of  claim 9 , wherein the connector includes a connector body in the cap discharge opening,
 wherein the connector has a hollow pipe shape, 
 wherein an end of the connector includes a connector flange having a diameter larger than a diameter of the cap discharge opening, and 
 wherein a hollow insertion member is in the outside transfer pipe. 
 
     
     
       11. The cap for a fuel tank of  claim 9 , wherein the elastic opening/closing section comprises:
 an opening/closing housing having a spring and an opening section at one side, and 
 a head section biased toward the connector by the spring, the head section opening the inside transfer path when the connector is in the cap body. 
 
     
     
       12. The cap for a fuel tank of  claim 9 , wherein the cap body has a flange section adjacent the fixed outer cap. 
     
     
       13. A method for supplying fuel continuously from a fuel tank, the—fuel tank including a tank body for storing fuel, the tank body having a threaded wall defining a fuel opening, and a cap covering the fuel opening, the cap comprising a threaded fixed outer cap screw-coupled to the threaded wall defining the fuel opening such that there is a gap between the threaded fixed outer cap and the threaded wall, the threaded fixed outer cap having a cap discharge opening for coupling the tank body to a transfer pipe and a pin hole providing an open two-way air path between inside the tank body and outside the fuel tank for maintaining an inside air pressure applied to fuel stored in the tank body; the method comprising:
 inserting a transfer pipe into the discharge opening to open an inside transfer path allowing fuel to be transferred through the cap; 
 locating a floater above a surface of fuel stored in the tank body such that the floater is exposed to the air above the surface of the fuel; 
 connecting a cap end of an air pipe to the pin hole; and 
 connecting a fuel end of an air pipe to a portion of the floater exposed to the air above the surface of the fuel.